Techniques for the isolation of nonparenchymal rat liver cells (NPC) in high yield and the subsequent purification and culturing of functional Kupffer cells (KC) have been developed. The influence of dietary zinc status and physiological stress on the zinc and metallothionein contents of hepatocytes and NPC will be determined. The characteristics of zinc accumulation by and efflux from resting KC and peritoneal macrophages will be elucidated. Similarly, biosynthesis and the level of the intracellular zinc storage protein, metallothionein, will be investigated. Studies concerning the influence of phagocytic cell activation on the metabolism and membrane transport of intracellular trace metals will be initiated.